Opening the CompanionKit C# Solution from the Windows Start menu starts VS10 with the error: One or more projects in the solution were not loaded correctly.

The Output window shows:

C:\Program Files (x86)\Gizmox\Visual WebGUI\Sources 4.0\Gizmox.WebGUI.Forms.CompanionKit\Gizmox.WebGUI.Forms.CompanionKitCS.4.0.csproj : error : Unable to read the project file 'Gizmox.WebGUI.Forms.CompanionKitCS.4.0.csproj'. C:\Program Files (x86)\Gizmox\Visual WebGUI\Sources 4.0\Gizmox.WebGUI.Forms.CompanionKit\Gizmox.WebGUI.Forms.CompanionKitCS.4.0.csproj(4099,7): The required attribute "Include" is empty or missing from the element .

The VB solution opens ok.